Abstract: A graphics system for providing two-sided lighting. The graphics system may include a media processor and a hardware accelerator. The media processor may be configured to receive a stream of vertices, and to perform a two-sided lighting computation on each vertex resulting in front color and back color for each vertex. The hardware accelerator may be configured to (a) receive the vertices of the first stream along with the front and back color for each vertex, (b) assemble the vertices into polygons, (c) compute an orientation for each of the polygons, (d) select the front color or the back color of the vertices forming each polygon based on a result of the orientation computation for each polygon, and (e) render each polygon using the selected color of the vertices forming the polygon.

Abstract: One embodiment of a method of performing a font operation involves receiving a set of font data identifying a font operation to be performed. If a first font data unit in the set indicates that a first coordinate should be a background color and transparent background is enabled, the method involves outputting an enable for a second font data unit in the set. The second font data unit indicates that a second coordinate should be a foreground color. The enable for the second coordinate is output instead of a disable for the first coordinate. If instead the first font data unit in the set indicates that the first coordinate should be a background color and transparent background is disabled, the method may involve outputting a disable for the first coordinate.

Abstract: A system and method for rendering a polygon, such as a triangle. The method may comprise receiving geometry data (or vertex data) defining vertices of the polygon. The method may compute initial vertex x,y values at end points proximate to each of the vertices of the polygon, and a slope value along each edge of the polygon. The computed slope may be a quantized slope value having a first number of bits of precision. The first number of bits of precision may produce inaccuracies for interpolated x,y values computed at the end points of an edge of the polygon. The method may then interpolate x,y values along each respective edge of the polygon using the computed slope along the respective edge of the polygon. Finally the method may store final x,y values for each respective edge of the polygon. The final x,y values comprise the interpolated x,y values for non-end points of the respective edge, and the computed initial vertex x,y values for each of the end points of the respective edge.

Abstract: A system and method for assigning operations to multiple pipelines in a graphics system is disclosed. The graphics system may include an arbitration unit coupled to a plurality of calculation pipelines. The arbitration unit is operable to provide graphics operations to selected ones of the calculation pipelines. Each of the calculation pipelines is operable to perform a graphics operation. Each of the calculation pipelines may include digital logic and/or a processing element for performing the graphics operations. An operation may be assigned to a pipeline if the pipeline is performing a low latency operation. A low latency operation may comprise an operation that is performed by one of the calculation pipelines in less time than a pre-determined number of clock cycles.

Abstract: A graphics system configured to apply multiple layers of texture information to batches of primitives. The graphics system collects primitives into a batch that share a common set of texture layers to be applied. The batch is limited so that the total estimate size of the batch is less than or equal to a storage capacity of a texture accumulation buffer. The graphics system stores samples (or fragments) corresponding to the batch primitives in the texture accumulation buffer between the application of successive texture layers.

Abstract: A system and method for rasterizing and rendering graphics data is disclosed. Vertices may be grouped to form primitives such as triangles, which are rasterized using two-dimensional arrays of samples bins. To overcome fragmentation problems, the system's sample evaluation hardware may be configured to over-evaluate samples each clock cycle. Since a number of the samples will typically not survive evaluation because they will be outside the primitive being rendered, the remaining surviving samples may be combined into sets, with one set being forwarded to subsequent pipeline stages each clock cycle in order to attempt to keep the pipeline utilization high.

Abstract: A system and method for packing pixels together to provide a increased fill rate in a frame buffer hardware in the graphics system. The graphics system may be configured to receive and rasterize graphics data at a faster cycle rate than the system's frame buffer memory fill rate. The output from the rasterization hardware may be stored in a FIFO memory that is configured to selectively shift pixels in order to improve fill rate performance. The FIFO memory may be configured to ensure that the pixels meet certain criteria in order to prevent page faults and interleave conflicts that could reduce the fill rate. The FIFO memory may also be configured to remove empty cycles that occur as a result of the pixel packing.

Abstract: A system and method for rasterizing and rendering graphics data is disclosed. Vertices may be grouped to form primitives such as triangles, which are rasterized using two-dimensional arrays of samples bins. Individual samples may be selected from the bins according to different criteria such as memory bank allocation to improve utilization of the system's rendering pipeline. Since the arrays may have more bins than the number of evaluation units in the rendering pipeline, the samples from the bins may be stored to FIFO memories to allow invalid or empty samples (those outside the primitive being rendered) to be removed. The samples may then be filtered to form pixels that are displayable to form an image on a display device.

Abstract: A graphics system may be configured to render anti-aliased dots in terms of samples and to generate pixels by filtering the samples. The pixels are supplied to one or more display devices. The means used to generate the samples may perform the computation of radial distance at positions on a grid in a rendering coordinate space, and interpolate estimates for the radial distances of samples around the dot as needed based on the radii at the grid positions.

Abstract: A graphics system configured to operate on a collection of vertices to determine mappings from an initial order to secondary and tertiary ordering. The initial order corresponds to the ordering of the vertices in an input buffer. The secondary (tertiary) ordering corresponds to the ordering of the vertices along a triangle major (minor) axis. The graphics system computes horizontal and vertical displacements along edges of the triangle in the initial ordering, and uses the signs of the horizontal displacements and vertical displacements to access a mapping table which determines the mappings. The mappings may be used to rasterize the triangle in terms of pixels (or samples).

Abstract: A graphics system and method for displaying lines on a display device. The system may comprise a sample buffer, a rendering unit and a sample-to-pixel calculation unit. The rendering unit may (a) generate a plurality of sample positions in a two-dimensional space, (b) determine a sample normal distance for each of the sample positions with respect to a line defined by the line-draw command, (c) assign sample values to the sample positions based on the sample normal distance of each of the sample positions, and (d) store the sample values in the sample buffer. The sample-to-pixel calculation unit may read sample values from the sample buffer, filter them to determine a pixel value, and transmit the pixel value to the display device. The rendering unit may render the line sample values with a narrower width to pre-compensate for the line-expanding effect of the filtering performed by the sample-to-pixel calculation unit.